1. Field of the Invention
This invention relates to a composition for use in treating benign prostatic hyperplasia, which comprises saw palmetto extract contained in a controlled delivery system. The composition is preferably administered orally, uses a controlled delivery system to provide a targeted, extended release of the saw palmetto extract into the bloodstream.
2. Related Art
Many men over the age of fifty commonly experience a condition known as benign prostatic hyperplasia, or BPH. BPH affects as much as 40% of the male population over the age of seventy. The condition is commonly recognized as a swelling of the prostate gland. This problem gradually manifests itself in the form of a) frequent urination, b) small discharge volumes and xe2x80x9cdribblingxe2x80x9d, and c) unsatisfying bladder evacuations. Waking up to urinate once or more each night is a typical sign of this problem. BPH is a chronic condition that tends to gradually worsen with age.
The increased incidence of BPH in older men may be due to the fact that as men age, testosterone levels tend to decline and estrogen levels rise. In the process, testosterone metabolism takes a different pathway, and testosterone is converted to dihydrotestosterone (DHT), a potent male hormone that causes prostate enlargement. The actions of DHT can be limited by restricting the enzymatic production of DHT from testosterone and/or blocking the direct pharmacological action of DHT at the receptor level. Current therapies for BPH focus on limiting the actions of DHT, and include: pharmaceutical intervention with 5-xe2x88x9d-reductase inhibitors such as finasteride (Proscar(copyright)); pharmacological intervention with xe2x88x9d-adrenergic blockers, such as terazosin HCl (Hytrin(copyright)), and doxazosin mesylate (Cardura(copyright)); prostatectomy; and administration of saw palmetto extract.
Extract of the saw palmetto berry (Serenoa repens) has been demonstrated to be effective in treating the symptoms of BPH in numerous clinical trials, including a number of double-blind studies. For example, a meta-analysis of existing clinical evidence for the efficacy and safety of the use of saw palmetto extract to treat BPH was published by Witt et al., JAMA (1999), 18:1604-1609. This analysis concludes that saw palmetto extract is effective in treating BPH, as compared with Proscar(copyright).
Saw palmetto extracts have been used in various products intended to treat BPH. For example, in U.S. Pat. No. 5,543,146, a composition for dietary supplements including pumpkin seed, extracts of saw palmetto, and various other components is disclosed. This composition is used as a dietary supplement for alleviating the symptoms associated with enlargement of the prostate gland.
In U.S. Pat. No. 6,200,573, which relates to a method for managing BPH, a combination therapy of an xe2x88x9d-adrenergic antagonist such as terazosin and a phyto-therapeutic agent such as saw palmetto extract is disclosed. The active ingredients may be administered in combination with diluents and other carriers, for oral or parental administration, or may be delivered by any conventional delivery system. It is also disclosed that the active ingredients may also be formulated into once-a-day or longer sustained release compositions, although no guidance is given in this regard.
U.S. Pat. No. 6,039,950 relates to a method of making medicinally-useful saw palmetto materials in pharmaceutically acceptable forms. It discloses compositional and activity fingerprints for use in processing saw palmetto materials to produce compositions suitable for use in clinical or veterinary settings to treat various conditions. The method involves measuring the bioactivity of a sample of saw palmetto extract using an androgen receptor binding inhibition assay.
U.S. Pat. No. 6,197,309 relates to a composition for preventing or improving disorders of the prostate gland. The composition preferably includes therapeutically effective amounts of vitamin C, vitamin B-6, vitamin E, zinc, glycine, L-alanine, glutamic acid, saw palmetto extract, Pygeum extract, pumpkin seed, stinging nettle, Echinacea, garlic, ginkgo biloba, and selenium.
Finally, U.S. Pat. No. 6,019,976 relates to therapeutic formulations containing saw palmetto extract, vitamin B-6, vitamin B-3, zinc, and L-arginine. The formulations are used to treat male pattern baldness by topical application to the hair. The formulations may also be provided in the form of a drink, or in a capsule formed of gelatin and glycerin.
Other compositions have been focused on treating smooth muscle spasms, such as those that occur in the bladder, prostate, and urethra, including the compositions disclosed in U.S. Pat. No. 4,725,593. Such compositions may be administered orally, by intravenous injection, or by topical application.
None of the methods or compositions discussed above address treating benign prostatic hyperplasia by administering saw palmetto extract in a controlled delivery vehicle for extended, targeted release of the extract in the small intestine. Further, none of the methods or compositions discussed above address a method of improving the delivery of saw palmetto extract by providing the extract in the form of an oral administration vehicle comprising a controlled release system.
This invention relates to a method for improving the efficacy and convenience of oral saw palmetto therapy in the treatment of benign prostatic hyperplasia, or BPH, through the use of a controlled release formulation. The controlled release formulation allows the targeted release of the extract in a specific part or parts of the digestive system, and the extended release of the extract over the course of digestion. The targeted release is designed to deliver the active agent, extract of the saw palmetto berry (i.e., especially the phytosterols contained therein), to the portions of the digestive tract most suited for its absorption. The extended release is also designed to deliver the extract over a period of time, determined by routine methods, to be of the optimum length for this type of therapy. The controlled release saw palmetto extract composition of this invention improves the effectiveness of saw palmetto therapy for BPH by optimizing the absorption of the extract within the digestive tract, maintaining a therapeutic level of the active agent in the bloodstream for a sufficient length of time so as to reduce the dosages and the frequency (i.e., preferably once a day). The composition of this invention also improves the efficiency of saw palmetto therapy by combining the saw palmetto extract with one or more additional antispasmodic agents.
The methods and compositions of this invention address the need in the art for a more effective and convenient BPH treatment, as set forth above. More specifically, one aspect of this invention provides a composition for use in treating benign prostatic hyperplasia and comprises a saw palmetto extract provided in a controlled release oral delivery formulation, which comprises, for example, a coating formed from a material impervious to acidic conditions in the stomach that is soluble in the duodenum and small intestine.
According to another aspect of this invention, a composition for improving the effectiveness of saw palmetto extract therapy comprises a saw palmetto extract provided in a controlled release oral formulation, which comprises a coating formed from a material impervious to acidic conditions in the stomach that is soluble in the duodenum and small intestine.
According to an additional aspect of this invention, a composition for improving the efficacy of saw palmetto extracts comprises an effective amount of a saw palmetto extract, and one or more antispasmodic compounds (compounds which reduce smooth muscle contractions) selected from the group consisting but not limited to extracts or tinctures of Belladonna alkaloid, Choleus Forskholi, European Goldenrod, Peppermint, and Passion Fruit seed.
A preferred composition of the present invention comprises a two-part hard shell capsule that encases a matrix holding from about 100 mg to about 1 g of saw palmetto extract, and more preferably about 320 mg of the extract.
According to a further aspect of this invention, an improvement in an orally-administered controlled-release composition comprising saw palmetto extract comprises a compound that minimizes smooth muscle contractions, the controlled release system being selected from the group consisting of microencapsulation in coatings of variable thickness, each with a different dissolution pattern; encapsulation in a material matrix that dissolves slowly in the neutral environment of the duodenum and small intestine; and binding with bioadhesives that adhere to the wall of the small intestine.
According to yet another aspect of this invention, a method of treating benign prostatic hyperplasia comprises the step of administering a therapeutically effective amount of a saw palmetto extract provided in a controlled release oral formulation that includes a coating formed from a material impervious to acidic conditions in the stomach, but which is soluble in the duodenum and small intestine.
According to an additional aspect of this invention, a method of improving the efficacy of saw palmetto extract treatment comprises the steps of providing a therapeutically effective amount of a saw palmetto extract in an oral formulation, and encapsulating the saw palmetto extract in a coating formed from a material impervious to acidic conditions in the stomach that is soluble in the duodenum and small intestine.
According to a further aspect of this invention, a method for improving the efficacy of saw palmetto extract treatment comprises the steps of providing a therapeutically effective amount of a saw palmetto extract, and further providing one or more antispasmodic compounds selected from the group consisting of extracts or tinctures of Belladonna alkaloid, Choleus Forskholi, European Goldenrod, Peppermint, and Passion Fruit seed.
It will be apparent to those skilled in the art that only the preferred embodiments have been described by way of exemplification, and that there are various modifications which fall within the scope of this invention. These and other aspects of the invention will be discussed in greater detail below.